A term used to describe a highly volatile dangerous situation (a fast food resturant where a signature item that is highly promoted is unaccessable to the consumer, despite the popularity of the meal) that requires immediate remedial action- such as the use of an emergency hotline, like 911. When presented with a situation such as this, the McGangsta will react with anger and hostility, due to the establishment's failure to serve and will contact authorities to report this emergency.
It is a term/ action one uses when an establishment cannot serve their food properly, which results in McGangsta's ignorance, improper use of an emergency line, and a few days in the lock up.

K'Mark'Tina: "WUT U SAY?!?! U AINT GOT NO WUT??. o HELL nah. i'm bout ready to get MCGANGSTA up in here! sheeeeet. THIS IS A EMERGENCEE!! i callin the po-lice up in here! i needz my mc nugget! 911!!! 911!!"

employee: "maam, that wont be necessary, we have plenty of other items...."